The Acute Pharmacodynamic Effects of Venlafaxine and Mirtazapine on Psychomotor Performance, Motor Activity, and Daytime Sleepiness / 대한정신약물학회지

ABSTRACT

OBJECTIVE: For the optimal use of antidepressants, it is important to consider the behavioral effects of drugs affecting the real lives of depressed patients, as there is little difference in therapeutic effects between drugs. The aim of this study was to determine the acute pharmacodynamic effects of two recently introduced antidepressants, venlafaxine and mirtazapine, on psychomotor performance, motor activity and daytime sleepiness. METHODS: Twelve healthy male volunteers received a single dose of venlafaxine 37.5 mg, mirtazapine 15 mg or amitriptyline 25 mg (positive control) at one-week intervals in a double-blind, placebo-controlled, crossover design. Volunteers wore an actigraph on their non-dominant wrist for the duration of each test day. A battery of psychomotor tests was performed prior to dosing and at 2 and 6 h post-dose. Subjective daytime sleepiness was also assessed at the end of each test day. RESULTS: Venlafaxine did not affect psychomotor performance, motor activity and daytime sleepiness. Mirtazapine decreased thresholds in critical flicker fusion frequency, increased reaction times in choice reaction tests, and increased peripheral reaction times in compensatory tracking tests. It also caused significant daytime sleepiness and decreased motor activity. CONCLUSION: The differences in the behavioral effect profiles presented in this study should assist in the selection or scheduling of antidepressants.